containerd/containerd · error

failed encoding size = %v

Error message

failed encoding size = %v

What it means

encodeSize in the bolt snapshotter metastore encodes an int64 size as a varint. It errors only if the encoded byte slice is empty after binary.PutVarint, which in practice never happens for any int64 value — the guard is defensive. If seen, it indicates a corrupted or misused metastore code path.

Source

Thrown at core/snapshots/storage/bolt.go:615

		if err != nil {
			return err
		}
		if err := bkt.Put(v.key, e); err != nil {
			return err
		}
	}
	return nil
}

func encodeSize(size int64) ([]byte, error) {
	var (
		buf         [binary.MaxVarintLen64]byte
		sizeEncoded = buf[:]
	)
	sizeEncoded = sizeEncoded[:binary.PutVarint(sizeEncoded, size)]

	if len(sizeEncoded) == 0 {
		return nil, fmt.Errorf("failed encoding size = %v", size)
	}
	return sizeEncoded, nil
}

func encodeID(id uint64) ([]byte, error) {
	var (
		buf       [binary.MaxVarintLen64]byte
		idEncoded = buf[:]
	)
	idEncoded = idEncoded[:binary.PutUvarint(idEncoded, id)]

	if len(idEncoded) == 0 {
		return nil, fmt.Errorf("failed encoding id = %v", id)
	}
	return idEncoded, nil
}

func adaptSnapshot(info snapshots.Info) filters.Adaptor {

View on GitHub (pinned to 4246446a2b)

Solutions

1. Report/inspect the size value being passed to putUsage; a non-int64 (e.g. float cast) caller bug is the only plausible cause
2. Update containerd to a current patch release to rule out an old defect
3. Rebuild/inspect the bolt database file (containerd metadata snapshot bolt db) for corruption

if size < math.MinInt64 || size > math.MaxInt64 {
    return fmt.Errorf("size out of int64 range: %v", size)
}

encoded, err := encodeSize(size)
if err != nil {
    log.WithError(err).Errorf("snapshot usage size encoding failed for size=%d", size)
    return err
}

When it happens

Trigger: putUsage calls encodeSize with a size value when storing snapshot usage; the error fires if binary.PutVarint returns 0 bytes written, which cannot occur with binary.MaxVarintLen64 capacity for valid int64 input.

Common situations: Essentially unreachable in practice; would only appear if the bolt snapshotter metastore code was modified or if instrumentation/wrapping changed PutVarint behavior.

Related errors

• failed encoding id = %v
• media type not found
• runtime not found in index
• no snapshotter set for container
• rootfs snapshot not created for container

AI-assisted analysis of containerd/containerd@4246446a2b (2026-09-02). Data as JSON: /api/errors/066b289f15ed77a2. Report an issue: GitHub.